The Role of TB-LAMP Method in Detecting Mycobacterium tuberculosis from Sputum of Patients Suspected of Having Pulmonary Tuberculosis.

BACKGROUND: Indonesia is one of the countries with the highest incidence of tuberculosis (TB) in the world. Appropriate diagnosis is an effort to control TB. The World Health Organization has recommended loop-mediated isothermal amplification (LAMP). In order to be applied routinely, it is necessary to do research to evaluate the LAMP method. METHODS: the research was a cross-sectional study and was carried out at the Clinical Microbiology Laboratory of the Faculty of Medicine, Universitas Indonesia, for 100 patients suspected of having pulmonary TB. Each patient handed over two direct sputum specimens. For each direct sputum specimen, an acid-fast bacilli (AFB) smear was carried out. Two direct sputum specimens from each patient were combined to produce mixed sputum. For each mixed sputum specimen, an AFB smear, Lowenstein-Jensen culture, and TB-LAMP were carried out. RESULTS: the percentage of LAMP (+) cells in mixed sputum that was AFB (-) was 32.78%. The TB-LAMP showed a sensitivity of 100% (95% CI 89.56-100%), a specificity of 69.64% (95% CI 55.74-80.84%), positive predictive value of 71.19% (95% CI 57.73-81.86%), and negative predictive value of 100% (95% CI 88.83-100%). CONCLUSION: TB-LAMP has both high sensitivity and negative predictive value.

Potential cross-reactivity of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) nucleocapsid (N)-based IgG ELISA assay for plasma samples from HIV-1 positive intravenous drug users (IDUs).

AIM: to evaluate the specificity of the SARS-CoV N protein-based IgG ELISA assay for detection of immunoglobulin G (IgG) in plasma samples obtained from HIV-1 positive and HIV-1 negative intravenous drug users (IDUs). METHODS: the SARS-CoV N gene was cloned into pQE-80L vector, and the constructs were transformed into Escherichia coli BL21. The 6x His-tagged N protein was expressed by inducing the bacterial cells with isopropyl-1-thio-D-galactopyranoside (IPTG) and purified by Ni-NTA affinity resin. The 6x His-tagged N protein was used as antigen for ELISA assay and evaluated for the serum samples from patients with SARS positive and the plasma samples from the HIV-1 positive and negative IDUs. RESULTS: all sera samples from patients with SARS positive were the ELISA positive (100% sensitivity). The ELISA assay yielded no positive results of the total 61 HIV-1 negative IDU samples (100% specificity) and two positive results of the total 68 HIV-1 positive IDU samples (97.06% specificity). CONCLUSION: the specificity of the SARS-CoV N protein-based IgG ELISA assay for the detection of the SARS-CoV N specific IgG in plasma samples from IDUs with HIV-1 positive is, therefore, questionable.

Surface plasmon resonance analysis for detecting non-structural protein 1 of dengue virus in Indonesia.

Dengue is an acute febrile disease caused by dengue virus (DENV) that is transmitted by Aedes sp., which causes serious health conditions in many countries. Non-structural protein 1 (NS1) is a co-factor for the RNA replication of this virus, which represents a new strategy for the identification of dengue. Prompt and accurate laboratory diagnosis of this infection is required to assist in patient triage and management, as well as prevent the spread of this infection. In the present study, we tested the potential of surface plasmon resonance (SPR) as a diagnostic tool for dengue infections. NS1 antigen protein was used as an analyte that targets anti-NS1 antibodies, with their interaction resulting in a change in the refractive index. In comparison to currently available gold-standard detection methods [enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR)], SPR showed a similar sensitivity but greater efficiency and simplicity in terms of infection detection. Out of 26 samples collected from patients with dengue in Indonesia, SPR was able to correctly identify all 16 positively infected individuals at a lower concentration and a shorter period of time compared to ELISA and RT-PCR. This study revealed that SPR is a promising tool for DENV detection and potentially other diseases as well.

The burden of diarrhoea, shigellosis, and cholera in North Jakarta, Indonesia: findings from 24 months surveillance.

BACKGROUND: In preparation of vaccines trials to estimate protection against shigellosis and cholera we conducted a two-year community-based surveillance study in an impoverished area of North Jakarta which provided updated information on the disease burden in the area. METHODS: We conducted a two-year community-based surveillance study from August 2001 to July 2003 in an impoverished area of North Jakarta to assess the burden of diarrhoea, shigellosis, and cholera. At participating health care providers, a case report form was completed and stool sample collected from cases presenting with diarrhoea. RESULTS: Infants had the highest incidences of diarrhoea (759/1,000/year) and cholera (4/1,000/year). Diarrhea incidence was significantly higher in boys under 5 years (387/1,000/year) than girls under 5 years (309/1,000/year; p < 0.001). Children aged 1 to 2 years had the highest incidence of shigellosis (32/1,000/year). Shigella flexneri was the most common Shigella species isolated and 73% to 95% of these isolates were resistant to ampicillin, trimethoprim-sulfamethoxazole, chloramphenicol and tetracycline but remain susceptible to nalidixic acid, ciprofloxacin, and ceftriaxone. We found an overall incidence of cholera of 0.5/1,000/year. Cholera was most common in children, with the highest incidence at 4/1,000/year in those less than 1 year of age. Of the 154 V. cholerae O1 isolates, 89 (58%) were of the El Tor Ogawa serotype and 65 (42%) were El Tor Inaba. Thirty-four percent of patients with cholera were intravenously rehydrated and 22% required hospitalization. V. parahaemolyticus infections were detected sporadically but increased from July 2002 onwards. CONCLUSION: Diarrhoea causes a heavy public health burden in Jakarta particularly in young children. The impact of shigellosis is exacerbated by the threat of antimicrobial resistance, whereas that of cholera is aggravated by its severe manifestations.

Diarrhoea episodes and treatment-seeking behaviour in a slum area of North Jakarta, Indonesia.

Visits to household during a census in an impoverished area of north Jakarta were used for exploring the four-week prevalence of diarrhoea, factors associated with episodes of diarrhoea, and the patterns of healthcare use. For 160,261 urban slum-dwellers, information was collected on the socioeconomic status of the household and on diarrhoea episodes of individual household residents in the preceding four weeks. In households with a reported case of diarrhoea, the household head was asked which form of healthcare was used first. In total, 8,074 individuals (5%)--13% of children aged less than five years and 4% of adults--had a diarrhoea episode in the preceding four weeks. The two strongest factors associated with a history of diarrhoea were a diarrhoea episode in another household member in the four weeks preceding the interview (adjusted odds ratio [OR] 11.1; 95% confidence interval [CI] 10.4-11.8) and age less than five years (adjusted OR 3.4; 95% CI 3.2-3.5). Of the 8,074 diarrhoea cases, 1,969 (25%) treated themselves, 1,822 (23%) visited a public-health centre (PHC), 1,462 (18%) visited a private practitioner or a private clinic, 1,318 (16%) presented at a hospital, 753 (9%) bought drugs from a drug vendor, and 750 (9%) used other healthcare providers, such as belian (traditional healers). Children with diarrhoea were most often brought to a PHC, a private clinic, or a hospital for treatment. Compared to children, adults with diarrhoea were more likely to treat themselves. Individuals from households in the lowest-income group were significantly more likely to attend a PHC for treatment of diarrhoea compared to individuals from households in the middle- and higher-income groups.